I need to recharge the ac in my 88 monte carlo ss and I have the tube and oil and r12, what's the best way for me to do it my self,run car with ac on max and add oil then start adding r12 how much r12 should I install?Thanks
ac recharging ???'s
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Not quite that easy. For starters, you'll need a vacuum pump to evacuate the system. Typically, a SBC R12 system on a G body equipped with an A6 compressor called for 3.50 pounds, an R4 compressor specs 3.25 pounds. I'd have to look up the oil capacity, and there is a method to determine how much oil needs to be added, you don't just add the entire specified amount to an existing sytem.
Really, better left to a professional, unless you have experience and the proper equipment already.
Really, better left to a professional, unless you have experience and the proper equipment already.
I would change all O rings and seals, the orifice tube and the receiver drier/accumulator the Schrader valves and the pressure switch(s).
Remove the compressor and drain as much oil as possible. Lay it on it's back and let it drain, turn the compressor shaft periodically.
Replace the oil and spread it around, the majority goes in the compressor but all parts need oil added to them. Too little oil and the system will fail too much oil and the system loses efficiency. Turn the compressor by hand to make sure you don't try to pump pure oil when first operated.
Pull a vacuum for several hours you need to get all the water out of the system. At sea level and 30 inches of vacuum water boils in the 70 degree range, if you are at high elevation or it is below 70 run the engine and heat everything up (do not run the AC just warm the engine compartment up). Then make sure the vacuum will hold overnight.
Hook up the R12 can. Bleed the air from the gauge hoses. Add the first pound of refrigerant without running the system by letting the vacuum pull it in as a liquid (Turn the can up side down.). Start the engine and add the rest of the refrigerant as gas (with the can right side up).
Lots of very knowledgeable folks here.
Remove the compressor and drain as much oil as possible. Lay it on it's back and let it drain, turn the compressor shaft periodically.
Replace the oil and spread it around, the majority goes in the compressor but all parts need oil added to them. Too little oil and the system will fail too much oil and the system loses efficiency. Turn the compressor by hand to make sure you don't try to pump pure oil when first operated.
Pull a vacuum for several hours you need to get all the water out of the system. At sea level and 30 inches of vacuum water boils in the 70 degree range, if you are at high elevation or it is below 70 run the engine and heat everything up (do not run the AC just warm the engine compartment up). Then make sure the vacuum will hold overnight.
Hook up the R12 can. Bleed the air from the gauge hoses. Add the first pound of refrigerant without running the system by letting the vacuum pull it in as a liquid (Turn the can up side down.). Start the engine and add the rest of the refrigerant as gas (with the can right side up).
Lots of very knowledgeable folks here.
Typical R4 systems use 3.25 lbs R12.
About 6-7 oz of mineral oil spread around. Compressor label says 6 oz., but one more oz. won't kill it. Probably 3 in compressor if new, 2 in the accumulator, and 1 each in evaporator and condenser. Or skip the evaporator and leave it at 6 oz.
About 6-7 oz of mineral oil spread around. Compressor label says 6 oz., but one more oz. won't kill it. Probably 3 in compressor if new, 2 in the accumulator, and 1 each in evaporator and condenser. Or skip the evaporator and leave it at 6 oz.
All the above is good advice. But you did not mention the conditions. Has the system been open to atmosphere? Is it original, closed, and has some pressure at all? Is it all new? The approach is different for each situation.
Get a new accumulator/dryer at minimum. A/C delco If the system is dead and even if it's never been opened, it won't hurt. The refrigerant went somewhere. Those accumulators aren't very expensive. GM p/n 2724683. Plus better dessicants nowadays. $20 thereabouts at rockauto.com
Is the compressor still free? Turn the end of the clutch and if the compressor turns freely (it's a pump so there may be a bit of pumping action which is normal) it may just need resealing. I'd go through the system with new O-rings and everything.
If you need a new compressor, I believe your p/n is 1131636. It's what is considered a short shaft compressor. About 9/16" shorter main shaft. No big deal overall, just uses a different p/n clutch than earlier models. The late 86 and 87-88 Cutlass V8 uses 1131622 which is 99.99% EXACTLY identical part for part compressor as the 636. With one lone exception. The 636 has a slightly larger pulley on it than the 622. A bigger pulley slows it down a little. Not sure a bigger pulley is a great thing, but probably not enough to notice. It's just slightly larger. If you really wanted to, you could get a 622 pulley and swap them out. A bit of work for hardly any gain, so probably not worth it, though.
If it has indeed never been open, you may not have to even flush it. If the compressor is locked or if you notice trash/dirt/debris, etc., in any of the lines, there's a problem and it will likely need total service.
If you have no garbage in the lines, and the compressor seems ok, check for residual oil around the front seal and around the shell casing ends around the compressor. These are typical and common leak points.
WHICH brings me to this- I'm tinkering with an R152a experiment and will be rebuilding/resealing a 622 R4 compressor here soon. It's the original one off my 87 442. It crapped out on me when I went to add refrigerant to it so I had to flush it and redo the system with all new GM parts and a new 622 compressor. The compressor is likely toast, so I may do a tutorial on how to remove the shell, install new Delco cylinder guts, and reseal the compressor. I just happen to have a few of the correct tools to do that and you never know, it may help someone out.
Is the compressor still free? Turn the end of the clutch and if the compressor turns freely (it's a pump so there may be a bit of pumping action which is normal) it may just need resealing. I'd go through the system with new O-rings and everything.
If you need a new compressor, I believe your p/n is 1131636. It's what is considered a short shaft compressor. About 9/16" shorter main shaft. No big deal overall, just uses a different p/n clutch than earlier models. The late 86 and 87-88 Cutlass V8 uses 1131622 which is 99.99% EXACTLY identical part for part compressor as the 636. With one lone exception. The 636 has a slightly larger pulley on it than the 622. A bigger pulley slows it down a little. Not sure a bigger pulley is a great thing, but probably not enough to notice. It's just slightly larger. If you really wanted to, you could get a 622 pulley and swap them out. A bit of work for hardly any gain, so probably not worth it, though.
If it has indeed never been open, you may not have to even flush it. If the compressor is locked or if you notice trash/dirt/debris, etc., in any of the lines, there's a problem and it will likely need total service.
If you have no garbage in the lines, and the compressor seems ok, check for residual oil around the front seal and around the shell casing ends around the compressor. These are typical and common leak points.
WHICH brings me to this- I'm tinkering with an R152a experiment and will be rebuilding/resealing a 622 R4 compressor here soon. It's the original one off my 87 442. It crapped out on me when I went to add refrigerant to it so I had to flush it and redo the system with all new GM parts and a new 622 compressor. The compressor is likely toast, so I may do a tutorial on how to remove the shell, install new Delco cylinder guts, and reseal the compressor. I just happen to have a few of the correct tools to do that and you never know, it may help someone out.
Awesome. Do you have a gauge set? If not- get one. You can't work on AC without a gauge set. Because I have found that a lot of systems will leak down to around 10psi or so. That means no moisture could have gotten in if there is any pressure at all. In those cases I will drain it down to 2psi and refill with the proper amount of freon. No need to add anything else and if there are no big leaks, compressor works, it should operate well. But you need gauges to know what is going on. Never assume anything. I also like to use an inexpensive digital postal scale so I can add exactly the right amount of freon- no guessing. Now, if you are at zero psi, moisture could have gotten in. No system is perfect and all will leak a tiny amount. Over time it can be totally emptied, but again, any pressure at all will keep moisture out, even 1psi. The problem now is using expensive R-12 to 'test' a system. You don't want it to leak right out and be a waste of money. An alternative is to use Enviro-Safe freon replacement. It is compatible with R-12, R-134, and all oils, even mineral oil. That is what I have in my original R-12 system. Not a peep out of it for 10 years now. So let's say you put in the Enviro-Safe and it leaks right out. OK, now we have a leak. We find the leak, fix it, and now we should replace the receiver/drier because it probably has too much moisture in it. Same thing if the compresser is the leak. New parts will require adding some oil to compensate. If you open the system, moisture gets in. Moisture is the enemy. Once that is all done we need to vacuum down the system. You need a good vacuum pump to do that because water boils at 29" vacuum and will be carried out of the system. The inexpensive venturi type pump Harbor Break sells will work, but it needs a very good air compressor to work at it's best. Once vacuumed down you see if it holds vacuum [gauges needed again] then you can fill and test. If all goes well you can stay with the Enviro-safe or fill with your R-12.
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